Decrypt given data previously encoded with chacha20 cipher algo. ChaCha20 is a stream cipher that uses a 256-bit key and a 64-bit nonce to produce a keystream for encrypting data. ChaCha20 was designed by Daniel J. Bernstein in 2008 as a more secure alternative to the Salsa20 cipher. ChaCha20 is considered very secure and is widely used in modern cryptographic protocols, including TLS and VPNs. Our decryption process assumes the IV string is prepended in the encoded string during the encryption process. You can not decrypt and get the correct results if the IV or passphrase mismatch occurs between encryption and decryption process.